W 13, RsCHzN 0 in acetone. Later reports by Hino and Sato14J5 indicated that ethyl aminomalonate did not dimerize to 21 at elevated temperatures. Our results were in agreement with these later reports; ethyl aminomalonate prepared according to the method of Schipper and Day16 could not be dimerized under various conditions. We therefore investigated the dioxopiperazinediol24 as a possible precursor to the ...